Variable electrical controlling element



Dec. 8, 1925. 1,564,555

A. N. GOLDSMITH VARIABLE ELECTRICAL CONTROLLING EIJEMENT Filed July 31. 1919 s Sheets-Sheet 1 Dec. 8 1925. 1,564,555

A. N. GOLDSMITH VARIABLE ELECTINICAL CONTROLLING ELEMENT Filed July 31. 1919 s SheetS- -Sheet 2 Dec. 8, 1925. 1,564,555

I A. N. GOLDSMITH VARIABLE ELECTRICAL CONTROLLING ELEMENT Filed July 31. 1919 3 Sheets-Sheet 3 36 Hlllllllllllli VENTOR Ag in ORNEY I uni'rlainlsrArns PAT FNT F CE;

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CONTROLLING ELEMENT.

Application filed July 31, 1am. Serial no. 314,480.,

To all whom it may concern:

Be it known that 'I, Amman N. GOLDSMITH, a citizen of the United States, and a resident of the borough of Manhattan, city, county, and State'of New York, have invented certain new and useful Im rovements in Variable Electrical Contro 'ng Elements, of which the following is a-specifioation accompanied by drawings. u

This invention relates to variable electri cal controllingelements, but more particularlyto apparatus and devices for varying inductance which may find application for instance, among other arts, in radio signaling systems, it being understood that the devices may be used wherever found appli-. cable in electrical systems of any character.

The primary object of the invention is to providea readymeans ofchanging the inductance of the desired. circuits conven iently and continuously, and I have found that an inductance in the field 6f which a conducting shield forming a short oii'ouited secondary, is adapted to be moved in one di' rection or another, or periodically intro-- duced orwithdrawn, forms an efliclent and satisfactory variable inductance. Obviously my invention contemplates relative move-- ment between a coil or coils anda shield or shields, however this may be accomplished.

In order to 'morereadily" understand my invention, I have shown it applied to a wave clianger for radio signaling apparatus, both for receiving and transmitting,'but this is merely for purposes of ill istration, in

order to indicate some of the uses and advantages of the invention.

Referring to the drawings, Fig. 1 is a view showing means for varying the coupling of a receiving station provided with a variable shieldinductance;

' Fig. 2 is a diagrammatic view partly in perspective showing a variable loading inductance'anda variable coupling;

. Figs. 3 and 4 are diagrammatic represen;

tations of oscillating vacuum tube transmitters to which the invention is applied; and

Fig. 5 is a diagrammatic representation of a quenched ga transmitter to which vention is app ied. V

Referring to the drawings and at first more particularly to Fig; 1, A represents an antenna grounded at B coupled to. suitable the inreceiver circuits having the. variable contransmission. from continuous waves. V

. denser F, detector G} and the telephones H.

The usual variable condenser J. is shown in the I antenna .A PQ represent respectively primary and secondary coupling coils of-a transformer between which is a shield O' which may be in the form ofa disk of conducting material as copper and may be of any suitable configuration.

In Flg. 1 is shown a mode of varying the mutual inductance between. the couplin coils P and Q by the motion in their mutua field" of the shield O. The mutual field of magnetic lines of force from coil P which passes through coil Q, as distinguished from the self-field of each coil, also passes at least -in. part through the conducting shield 0. As the shieldO is moved or rotated rela-' tively to or-about any axis 0 in substan tially any "fashion, the interlinkage of mutual flux through it will alter and in 0011- be altered. I thus have a means of continuously varying the mutual inductance'between two coils by the motion in their mutual field of a shield of conducting material.

This principle has been previously utilized.

by mefor another purpose infmy copending applications Serial #313,691 for my modu- 1 tone I In the present appligationthe coils P and Q and shield 0 together form 'a. variable,

- mutual inductance of the shield type. The;

mutual inductanceis that between the coils P and Q and the shield ay consist as sliown.

# take any other 'de-- of the disk 0 .but ma sired or suita le form, some of which are my copending application Serial illustrated herein, and to be described. The

shield may the coils and Q, 'which may, if desired, be

flat spirals as shown in Fig. 2 and when the shield is entirely inserted as shown in Fig. 1, V the. mutual inductance will be a minimum tv as explained in connection with my modula be progressively inserted-between tion receiver in my application Serial Q It is to be understood that I the shield O may be movedor manipulated by any suita'ble form of, operative mechanical means (not shown), and the outline or contour of sequence its shielding eflect upon coil P will 1 the shield, and its conductivity. are. deter-' minable at will, so that practically any 'des'iredflawof inductance variation with a given series of settings of the shield may be obtained. Furthermore, practicallyany law I of mutual inductance variation can-be sim1- e larly obtained by the prope r choice of the same conditions.

The entrant edge or advancing bontour of? the shield of conducting material, which passes over or into the inductance is of importance in that it determines, in part, the

law connecting motion of'the shield and the inductance of the coil which is being.

shielded. The 'drop' of inductance with a curved edge is more gradual and extends more nearly evenl over the entire range of motion of the shield. Another even more important-advantage is that the increase in resistance during shield insertionas well as theterminal resistanceis considerably less.

This is to be ascribed to the'nature of the eddy current paths in the shield, which becomes clear upon a detailed examination of them.

In Fig. 2, in addition to the shield inductance formed by-the' coil T and shield 12, l

have illustrated a combined arrangement of shield inductances for the coupling coils 8 and 9 which is also a variable shield mutual inductance, because the primary coil 8 which is variable by means of the shields, is coupled to the similarly variable secondary 9 through a variable shield mutual inductance.

In" this instance, the Shields 10, 11, and 12 are arranged adjacent and betweenv the coils 8 and 9 as indicated and adjustably mounted by means of set screws 13 on a common operating shaft adapted to be manipulated by the handle 15 to swing the shields into and out of shielding position. The shields 10, 11; and 12 need not necessarily be on one operating shaft, but may be independent of one another or"else mutually interconnected in any desired-.manner. The con-" loading coil T may be operatively connected to the shaft 14 of the shields 1o, 11, and 12' by any suitable means as the belt orchain 16, so that .a completely uni-control deyice is produced. .As the wave length is increased by increasing the inductance of all the coils T, 8, and 9, the coupling between coils 8 and 9 will also be automatically increased by the proper amount. It is to be understood that the design of Fig. 2 is merely illustrative and the arrangement and shape of the various shields, shield inductances, and variable shield mutual inductances may be varied in accordance with any of the modifications herein disclosed, or

with the principlesoi my invention, without departing from the 'spirit of the invention as claimed by me in the claims forming part of this specification.

changed in various particulars in accordance Fig. 3'shows the invention applied to a l form of unicontrol bulb or vacuum tube radio telegraph'transmitter, which may be made a radiophone transmitter by suitable alterations in the circuits, well. understood ,by those skilled in the art, which however,

- do not alfe ct the principles of my invention.

- In Fig. 3, the oscillating vacuum tube represented at 17 may be of the three element or any other suitable type, having the heated filament 18, the plate 20 and the grid '19. The circuit shown in the example may be termedia series plate feed circuit, and. is known as such, since the plate circuit generator 21' is in series with the oscillating The regenerative coup-ling antennacircuit. between the coupling coils 22' and '23, by means of'which the plate and grid circuits are also coupled, and sustained oscillations maintained, may be of thecombine'd shield inductance and variable shield mutual inductance type as illustrated'in Fig. 2 for instance, but'is here shown in Fig. 3 diagrammatically for convenience andto avoid repetition of drawings. It is to be understood however, that any ot the other forms of inductance controlling devices illustrated and described: may be used as desired, so that, as the antenna wave length is altered by changes in the shield inductance formed by coil 22 and its shields, corresponding and suitable changes are made in the grid, circuit shield inductance formed by coil 23 and its shields, and also in the shield coupler betweencoils 22 and 23. :The shield inductance formed by the loading coil 24 and shield 25 maybe used in the antenna as shown if desired. Though the end connections to coil 22 are shown as movable, theyare, in

general, fixed once for all when the set 1s connected to a given antenna for use throughout a given wave length range. All var ation ofi wave length Wltlllll this range thereafter may, in general, be'obtaiucd by motion of the shields 10, 11, and 12.

' In Fig. 4 is shown another bulb or vacuum tube oscillator of the uni-control type, but in this instance the circuit is of the parallel plate feed form, in which the plate circuit-generator 21, in series with the radio frequency choke coil v26vis connected to the filament 18 and plate 20 of the tube in parallel with the oscillating circuit induct- ,ance 27, and the remainder of the oscillating circuit including the antenna A and inductance 28. diagrammatically shown for the inductances Variable shields 29 and 30 are the circuits by means of the inductances'27 and 28 and themaintenance of a suitable regenerative, coupling between-the induct 'ances,' which-are respectively in the plate and grid circuits, is- Obtained bymanipula I tionpi' the shields I29 and 30, which-also. mutual field of the coils, said coils and shield control the mutual inductance of thecoupler.

As mentioned in connection with Fig. 3, the

terminal connectionslto coils 27 and 28 are,

. 1ngenera1, stationa ry when once. the set is installed, and shield movement only is decoils. y

3. A variable radio coupler comprising a pended upon for wave changing.

In Fig; the invehtion is shown appliedto a uni-control quenched spark transmitter, in which the alternator 31 is connected [through the key 32 to the primary 33 of the high tension transformer, the secondary 34 of which includes in its circuit the secondary capacity 35, the quenched spark gap 36, and the primary coupling coil '38, coupled V to'the antenna inductance The inductances 38 and 39 are shown diagrammatically as shield inductances, as indicated by the shields 40, 41, andv42, and this construction i also forms a combined sliield inductancc'and variable shield mutual inductance in ac cordance with Fig. 2 for instance, al-

- tual inductance.

ventlon involve a coll'or coils in the mag though other forms of devices may be used 30 as hereinbefore described and explained.

The-various forms of my invention'contemplate a variable couplerwhich' I have termed 'ashield coupler; or "they involve both a variableinductance and a variable coupler which ,I--'have termed acombined shield inductance and variable shield mu- The principles of my innetic' field of which a body or bodies of con ducting material are moved-or inserted in such manner that the magnetic fields of the eddy ,currehts. induced in such bodies change the effective inductance, mutual inductance or both, of the coil or coils, as said eddy cur rents are progressively altered by the .mo-

tion, insertion, or withdrawal of said 'con' ducting body or bodies.

While I have shown various special forms of application of a shield coupler to uni-con tro-lo'r multi-control receivers and transmit ters of various types,- I am'n'otto be restrict- 4 ed to the particular forms shown, but desire to be understood as including within my to which they are applicahle- 1 invention, shieldcoiiplers, or combinations of these in difl'erent forms in any receiver. or transmitter orany other electrical device.

\ I claim. and desire to obtain by L etters Patent the following.

1. A variable radio coupler comprisingcoaxial current carrying coupling'coils and a paral'lelshield of conducting. material in the mutual field of the coils, said coils and .shield being relatively movable ina directiontransverse to the axis of the coils whereby the l coupling between'the coils may be.

varied.

2. A variable 'radiQ coupler. comprising high-frequency coaxial current carrying coupling coils and a parallel shieldpf cohducting material intermediate 'to and inthe being located in.close proximity to each.

transverse to the axis'of .the coils whereby,

other'and relatively movable in a direction the shield, may be withdrawn to obtain max-- imum variation. of the coupling between the pairof radio frequency coaxial current carrying couplingcoils and afparallel short 7 ci'rcuited secondary of conducting material intermediate to the coils, said' cdils and secondary being relatively movable in a direction transverse to the axis of the coils and located in close proximity to each other.

A variable coupler; comprising .coaxial coupling coils, and a flat shield ofconduct-' ing material in the mutual' field-5f said coils,

said" coils and shield being slidable relative to each other-in a directiontransverse to-the' axis of said coils.

6. A variable coupler, comprising fiat coaxial coupling coils, and'an intermediate flat shield f conducting material substanradio frequency current carrying coupling coils fixed relative to each other, and a. shorp proxi tiall'y'parallel thereto'in themu'tual fieldof t0 cover various sections 0 the-coils, said shield bein "adjustable in a xdirection transverse to the axis of the coils I 7. A *variable coupler, comprising flat coaxial couplingcoils and a fiatshield of conducting material substantially parallel; thereto in the mutuall field of-the coils, saidr conductingbody being rotatable in a plane transverse to the axis offsaid coils. I 8. A variable coupler,'comprising coaxial flat cou'pling coils and anintermediate flat shield of conducting material substantially parallel and inclose proximity thereto, said coils and shield being slidable relative .to "each other in a direction transverse to the axis 9f said coils, to cover various sections of the surface of the coils.

9. A variable coupler comprising current carrying coupling coils fixed relative to each other and a parallel short circuited second- ;ary of conducting ma-terial in the .mutual field of the coils, .said coils and secondary rality of coaxial current carrylng' coupling; coils and a plurality of parallel shields of conducting material adjacent said coils, said coils and shields being relatively adjustable in a direction transverse to the axis of said coils for varying the coupling.

11. A variable coupler comprising a plurality of coaxial current carrying coils,- a

' shield of conducting material in the mutual field of. two of the coils, a second shield oi conducting material in the self field of one of the coils, and means for relatively adj usting said shields and coils in a direction transverse to the axisof said coils.

12. A variable coupler comprising a plurality of coaxial current carrying "coils, a

v I I shield conducting material parallel to and in the mutual field of two of said coi'ls'and -asecond shield of, conducting material parallel to andin the self field of another of q 7 said'coils and means for relatively adjusting said shields and coils in a direction transverseto the axis of the c0115.

13. A variable coupler comprising a: plu- 'r'al-i-ty of flat coaxial current carrying coils,

a flat shield of conducting material'par'allel to and in the mutual field of two of said coils and a second flafi shield of conducting material parallel to one of 'said coils and means for relatively adjusting said shields and coils in a direction transverse to the axis of the coils. v

In testimony whereof have signed this specification.

ALFRED GOLDSMITH. 

